Optical fiber telecommunications cables are generally intended to be laid in ducts of urban or long-haul transmission systems. To facilitate its positioning within a duct, a telecommunications cable must have a certain robustness to withstand the traction and the mechanical stresses of installation, as well as a certain flexibility in at least one bending direction. In addition, a telecommunications cable must generally be able to withstand conditions of use over a wide temperature range, possibly between −40° C. to +60° C., which may cause expansions and compressions in the cable jacket. It is known to supplement the telecommunications cable with strength members, which absorb the mechanical stresses and thereby protect the optical fibers arranged in the cable. Strength members may be positioned in the central area of the cable or on its periphery.
For example, International Publication No. WO 2006/034722 and International Publication No. WO 2006/034723 describe cables with micromodules having two circular strength members located longitudinally in the cable jacket surrounding the micromodules.
U.S. Pat. No. 5,050,957 describes an optical fiber cable in which optical fibers are placed in a tubular element filled with a filler composition. A jacket surrounds the tubular element and strength members are arranged in the jacket against the tubular element. In one of the examples of this document, the strength members follow the outer periphery of the tubular element. The cable described in this patent, however, is not a cable with micromodules.
U.S. Pat. No. 5,109,457 and U.S. Pat. No. 4,844,575 each describe an optical fiber cable including bundles of fibers assembled and placed in a tubular element filled with a filler composition. A jacket surrounds the tubular element and circular strength members are arranged in the jacket against the tubular element.
International Publication No. WO 92/01962 describes an optical fiber cable comprising at least one so-called package of optical fiber ribbons and at least one reinforcing member.
U.S. Pat. No. 5,155,789 (and its counterpart French Patent Publication 2,706,218) and U.S. Pat. No. 5,671,312 (and its counterpart French Patent Publication 2,665,266) disclose optical fiber cables that include several micromodules of optical fibers, wherein each optical fiber micromodule is enveloped by a retaining jacket enclosing several fibers.
There remains, however, a need for an optical fiber telecommunications cable that possesses a reduced diameter, as well as satisfactory robustness and water-blocking properties, and yet can be manufactured at lower cost than conventional telecommunications cables.